What’s Vulnerable › Vulnerabilities
CVE-2026-4395: Heap-based buffer overflow in wc_ecc_import_x963_ex KCAPI path
- Severity: critical (CVSS 9.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-03-19 · updated 2026-06-17
- Weakness: CWE-122
Description
Heap-based buffer overflow in the KCAPI ECC code path of wc_ecc_import_x963_ex() in wolfSSL wolfcrypt allows a remote attacker to write attacker-controlled data past the bounds of the pubkey_raw buffer via a crafted oversized EC public key point. The WOLFSSL_KCAPI_ECC code path copies the input to key->pubkey_raw (132 bytes) using XMEMCPY without a bounds check, unlike the ATECC code path which includes a length validation. This can be triggered during TLS key exchange when a malicious peer sends a crafted ECPoint in ServerKeyExchange.
Affected products
- wolfSSL: before 5.9.0 — fixed in 5.9.0
How to fix
Upgrade to a fixed version: wolfSSL 5.9.0. Check the vendor advisory for mitigations.
References
Get alerted when CVE-2026-4395 or the next vulnerability affects your stack